Several warning lights are on and the scan tool cannot communicate with several modules.
The CAN bus is not terminating or is shorted, so modules cannot exchange frames.
Suggested test plan
- Measure DLC CAN resistance.
- Check for shorts to power and ground.
- Inspect the network harness.
- Restore termination and re-test communication.
Safety: 12 V systems are low voltage but can still cause burns and fire. Disconnect the battery before working on wiring and never short a battery terminal.
CAN is a differential bus: two 120 Ω terminators in parallel read about 60 Ω. Multiple offline modules point at the bus itself.